The present invention relates to a fuel supply system that is installed in a fuel tank of a vehicle or the like for raising a pressure of a fuel and supplying the fuel to an injector injecting the fuel to an engine.
Hitherto, a system disclosed in the U.S. Pat. No. 5,392,750 is known as a fuel supply system for supplying fuel to an internal-combustion engine. Another fuel supply system as disclosed in the Japanese Utility Model Publication (unexamined) No. 109465/1992 is also known. In the construction of these fuel supply systems, a hollow cylindrical fuel filter is disposed on the outer circumference of a fuel pump, thus forming a fuel supply system.
However, in the construction disclosed in the U.S. Pat. No. 5,392,750 and the Japanese Utility model Publication (unexamined) No. 109465/1992, the hollow cylindrical fuel filter occupies the outer circumferential portion of the fuel pump. Accordingly, in order to form a pump module by uniting other fuel system parts, it is necessary for the fuel system parts to be mounted on further outside in radial direction or mounted in axial direction. Hence a problem exists in that volume of the entire pump module becomes large.
In the case of mounting the fuel system part on the outside in radial direction, the pump module becomes large in outer circumferential diameter. Hence another problem exists in that a tank hole through which the pump module is inserted in the fuel tank needs to be large in diameter.
A further system disclosed in the International Publication No. WO96/23966 is also known as a conventional fuel supply system. A still further system as disclosed in the Japanese Patent Publication (unexamined) No. 18932/1998is also known. In the construction of the fuel supply system disclosed in the No. WO96/23966, a C-shaped fuel filter is mounted on an outer circumferential portion of the fuel pump over approximately half of the circumference. Fuel system parts such as fuel level gauge are disposed in a space portion on the remaining side of the outer circumferential portion of the fuel pump where the fuel filter is not disposed, thus forming a the fuel supply system.
In the construction of the fuel supply system disclosed in the Japanese Patent Publication (unexamined) No. 18932/1998, a case for a fuel filter provided with a C-shaped filtration element inside thereof is D-shaped in section. Fuel system parts such as sensor for a fuel level gauge are disposed in the portion formed by cutting a cylindrical member, thus forming a fuel supply system.
However, in the construction of the fuel supply systems disclosed in both No. WO96/23966 and Japanese Patent Publication (unexamined) No. 18932/1998, since the filtration element of the fuel filter is C-shaped, a problem exists in that the area for filtering the fuel is small as compared with a system having a hollow cylindrical fuel filter.
The present invention was made to solve the above-discussed problems and has an object of obtaining a fuel supply system in which the filtration area of the fuel filter is increased without enlarging outer diameter of the fuel supply system and outer diameter of a tank hole through which a pump module is inserted in the fuel tank.
A fuel supply system according to the invention comprises a fuel pump installed in a fuel tank for raising a pressure of a fuel and supplying the fuel to an injector of an internal-combustion engine, a fuel pressure regulator for discharging a surplus of the fuel discharged from the fuel pump as a surplus fuel from a fuel passage into the fuel tank and regulating the pressure of the fuel, and a fuel filter having a hollow cylindrical filter case in which a filtration element for filtering the fuel discharged from the fuel pump is accommodated, wherein the filter case is provided with a holding hole for holding the fuel pump, a center line of the holding hole is formed eccentric with respect to a center line of the filter case by a predetermined distance, and a first enlarged space portion is formed at a part surrounded by an outer circumferential portion of the fuel pump and an outer circumferential portion of the filter case.
Fuel system parts such as fuel pressure regulator are accommodated in the first enlarged space portion.
A second enlarged space portion for accommodating a lead wire of a fuel level gauge is formed between an inner circumferential wall of the filter case and the outer circumferential portion of the fuel pump.